Saturday, 15 July 2017

When is history not history?

Just looked at the local real-estate map, as I do every so often, to see if anything nearby has come on the market, and at what price.

Zillow is showing a lowball Guesstimate for my house. Like, $80K less than a few days ago. WTF?

Look at the Guesstimate history chart thingy. No sudden drop. It's always been this low.

Which it, y'know, hasn't, but since it's always been bits in Zillow's computer and not ink on published paper, good luck proving anything. Computer databeese are so handy! There's no need for physical memory holes; just change the way a figure is calculated or displayed, and history will follow.

It's not the whole neighborhood, nor just my house. The house to the west has dropped by almost exactly the same amount. Two doors down has dropped by a little, as has next door to the east. Hm. Others are up, and some others are down. Perhaps "last remodel year" is suddenly a much larger factor than it was last week? So "Guesstimate history" is not a history of the Guesstimate, but a reconstruction of what the Guesstimate would have been using the current formula? (And meanwhile people keep telling me that Zillow's numbers for this area are - or, rather were, before the sudden drop - unrealistically low. And there's yet another massive business development in the works nearby, which should shortly be driving up local housing demand.)

Meanwhile, Google Finance's "technology" index is still being calculated based on AABA's last price being $123.47, up 134.78%. That the illusory change seems to be keeping the index permanently in positive-change territory says something about how the calculations are done, and it's not something good.